The second distance between the stick and the bottom of the cliff was five hundred feet.

These measurements finished, Cyrus Harding and the lad returned to the Chimneys.

The engineer then took a flat stone which he had brought back from one of his previous excursions, a sort of slate, on which it was easy to trace figures with a sharp shell.  He then proved the following proportions:—­

15:500::10:x

         500 x 10 = 5000

5000 / 15 = 333.3

From which it was proved that the granite cliff measured 333 feet in height.

Cyrus Harding then took the instrument which he had made the evening before, the space between its two legs giving the angular distance between the star Alpha and the horizon.  He measured, very exactly, the opening of this angle on a circumference which he divided into 360 equal parts.  Now, this angle by adding to it the twenty-seven degrees which separated Alpha from the antarctic pole, and by reducing to the level of the sea the height of the cliff on which the observation had been made, was found to be fifty-three degrees.  These fifty-three degrees being subtracted from ninety degrees—­the distance from the pole to the equator—­there remained thirty-seven degrees.  Cyrus Harding concluded, therefore, that Lincoln Island was situated on the thirty-seventh degree of the southern latitude, or taking into consideration through the imperfection of the performance, an error of five degrees, that it must be situated between the thirty-fifth and the fortieth parallel.

There was only the longitude to be obtained, and the position of the island would be determined, The engineer hoped to attempt this the same day, at twelve o’clock, at which moment the sun would pass the meridian.

It was decided that Sunday should be spent in a walk, or rather an exploring expedition, to that side of the island between the north of the lake and Shark Gulf, and if there was time they would push their discoveries to the northern side of Cape South Mandible.  They would breakfast on the downs, and not return till evening.

At half-past eight the little band was following the edge of the channel.  On the other side, on Safety Islet, numerous birds were gravely strutting.  They were divers, easily recognized by their cry, which much resembles the braying of a donkey.  Pencroft only considered them in an eatable point of view, and learnt with some satisfaction that their flesh, though blackish, is not bad food.

Great amphibious creatures could also be seen crawling on the sand; seals, doubtless, who appeared to have chosen the islet for a place of refuge.  It was impossible to think of those animals in an alimentary point of view, for their oily flesh is detestable; however, Cyrus Harding observed them attentively, and without making known his idea, he announced to his companions that very soon they would pay a visit to the islet.  The beach was strewn with innumerable shells, some of which would have rejoiced the heart of a conchologist; there were, among others, the phasianella, the terebratual, etc.  But what would be of more use, was the discovery, by Neb, at low tide, of a large oysterbed among the rocks, nearly five miles from the Chimneys.